13-E/4.1M Simple epi-/metaphyseal, medial condyle, Salter-Harris IV
This very rare fracture occurs mainly in children over 12 years of age. According to the AO pediatric documentation, they account for less than 5% of all intraarticular fractures of the child's elbow. It is characterized by a simple epiphyseal fracture combined with a metaphyseal fragment (Salter-Harris IV) on the medial side of the distal humerus.
The metaphyseal fragment may vary in size. The classification is independent of fragment size and displacement. These fractures are nearly always complete and unstable.
Radiologically this fracture can be difficult to diagnose if it is minimally displaced. The fat pad sign is an important indirect indicator of an intraarticular injury.
Ultrasonography and arthrography can help to verify the diagnosis.
Older child (older than 6 years):
Medial condylar fractures extending into the medial column of the distal humerus are rare and occur mostly in older children as shown in this example
This child is approaching skeletal maturity
In the majority of the cases the fracture is seen in the AP view